It is seven times as salty as the sea, pitch dark and 13 degrees below freezing. Lake Vida in East Antarctica has been buried for 2800 years under 20 metres of ice, but teems with life.

The discovery of strange, abundant bacteria in a completely sealed, icebound lake strengthens the possibility that extraterrestrial life might exist on planets such as Mars and moons such as Jupiter's Europa.

"Lake Vida is a model of what happens when you try to freeze a lake solid, and this is the same fate that any lakes on Mars would have gone through as the planet turned colder from a watery past,"...